This invention relates to an improved process for producing polyether-containing compositions and more specifically to an improved process for stabilizing a polyether composition prepared from one or more alkylene oxides using an amine initiator. In another aspect the present invention is an improved process for additionally neutralizing the alkaline catalysts used in the production of amine-initiated polyethers. Polyethers, and especially polyether polyols prepared from alkylene oxides have been utilized in lubricants, emulsifiers, plasticizers, solvents and as intermediates in the preparation of polyurethane and polyurethane-modified polyisocyanurate foams.
In general, the production of a polyether from alkylene oxide(s) is ordinarily carried out by the addition of the alkylene oxide(s) to an initiator compound, in the presence of an alkaline catalyst. It has been found very advantageous to use amine-containing initiator compounds in this reaction to achieve a good balance of product properties and process advantages.
It is well known in the preparation of the polyether compositions from alkylene oxides that, after preparation, the products typically require adequate neutralization before the polyethers can be used due to the residues of the alkaline catalysts. This is especially true in the case of such compositions which are used as the intermediates for preparation of urethanetype polymers. If not neutralized sufficiently, the residues tend to catalyze further reactions of the polyethers where such further reactions either are undesirable or are desired to be more controlled and/or predictable. As taught in U.S. Pat. Nos. 4,521,548, 3,299,151, 3,000,963, 3,016,404 and 4,110,268, many types of acids can be used to neutralize the alkaline catalyst. It has been found, however, that the polyether polyol compositions prepared using amine initiator compounds cannot be neutralized and/or stabilized sufficiently using known neutralization compounds and techniques for use in foamable urethane polymers. The rate and amount of foaming of the urethane polymers are generally not sufficiently predictable or reproducible between various samples and the polyols produced tend to have very unsatisfactory dark colors.